When the New Orleans Saints begin training camp practices on Friday,four key players won't be on the field, but instead, the PUP (physically unable to perform) list.

Center Max Unger, left tackle Terron Armstead and guard/center Senio Kelemete and linebacker Dannell Ellerbe all have a spot on the PUP list.

Unger and Armstead are not a surprise, as both are recovering from offseason surgery. Ellerbe isn't a surprise, as he's seemingly always injured since joining the Saints in 2015.

Kelemete is a surprise, and a bigger loss than some may realize considering the thin offensive line unit.

Unger, a standout center, is expected to be back from offseason foot surgery by week 3 of the preseason, according to Payton. Kelemete was a likely candidate to serve as the starting center during camp until Unger's return. The nature of Kelemete's injury is unknown.

Players on the PUP list do not count against the training camp roster and can be taken off the list at anytime during training camp or the preseason.

However, if a player begins the season on the PUP list, they are not available to return to the 53 man roster until after sitting out 6 weeks.

Armstead, who underwent surgery on a torn labrum in his shoulder last month, is a likely candidate for the regular season PUP designation.